@edgarblythe,
I don't know whether the issue of superdelegates has been raised in this thread (pardon me for not reading 120+ pages of comments), but it's definitely a thorny problem for Bernie:
"By the 1980s, the party elites felt left out of the process, bereft of all influence, and they thought their absence had hurt the party when weaker candidates like George McGovern and Jimmy Carter were nominated. Jim Hunt, Governor of North Carolina, was commissioned to fix the alleged problem, and by 1984 the Superdelegate system was implemented. Democrats thought that by giving more power to party leaders, it would prevent “unelectable” candidates, beloved by the populace, from costing them the general election."
" The Democratic nominee for president is decided based on which candidate wins the most delegates. You will find conflicting information about how many there are in 2016, but according to the AP, the delegate total is 4,763. It takes 2,382 of those to secure the nomination. And of the 4,763, 712 are “Superdelegates”—about 15 percent of the overall total."
"The (712 superdelegates) are not decided by each state’s popular vote, but rather by individuals who are given a vote by the Democratic party. They are free to choose whoever they want at the national convention, regardless of how the vote went in their home state."
http://www.pastemagazine.com/articles/2016/02/after-sanders-big-win-in-new-hampshire-establishme.html
The article plays down the importance of superdelegates. But if it takes 2,382 delegates to win the nomination, the 712 superdelegates is 30 percent of the number needed to win the nomination.And nearly all of the superdelegates are Democratic Party hacks whose party support in their own political careers depends on doing what the national party bosses tell them to. And the bosses want them to support Hillary Clinton.
If that weren't enough of a hurdle, most Black Democrats are already in the Clinton camp, even if this is largely by force of momentum and many are lukewarm about Hillary. In states like South Carolina where more than 50 percent of registered Democratic voters are Black, that could be a serious problem unless Sanders manages to woo them away. While Sanders appeals strongly to young voters (and presumably by extension to young Black voters), young voters are a minority of Democratic voters in most states.